You can do all of that in fetch really easily with the init object.

   fetch('https://api.example.com/data', {
  headers: {
    'Authorization': 'Bearer ' + accessToken
  }

})

There are pretty much two usage patterns that come up all the time:

1- automatically add bearer tokens to requests rather than manually specifying them every single time

2- automatically dispatch some event or function when a 401 response is returned to clear the stale user session and return them to a login page.

There's no reason to repeat this logic in every single place you make an API call.

Likewise, every response I get is JSON. There's no reason to manually unwrap the response into JSON every time.

Finally, there's some nice mocking utilities for axios for unit testing different responses and error codes.

You're either going to copy/paste code everywhere, or you will write your own helper functions and never touch fetch directly. Axios... just works. No need to reinvent anything, and there's a ton of other handy features the GP mentioned as well you may or may not find yourself needing.

Interceptors are just wrappers in disguise.

    const myfetch = async (req, options) => {
        let options = options || {};
        options.headers = options.headers || {};
        options.headers['Authorization'] = token;
    
        let res = await fetch(new Request(req, options));
        if (res.status == 401) {
            // do your thing
            throw new Error("oh no");
        }
        return res;
    }

Convenience is a thing, but it doesn't require a massive library.

That fetch requires so many users to rewrite the same code - that was already handled well by every existing node HTTP client- says something about the standards process.

It could also be trivially written for XMLHttpRequest or any node client if needed. Would be nice if they had always been the same, but oh well - having a server and client version isn't that bad.

Because it is so few lines it is much more sensible to have everyone duplicate that little snippet manually than import a library and write interceptors for that...

(Not only because the integration with the library would likely be more lines of code, but also because a library is a significantly liability on several levels that must be justified by significant, not minor, recurring savings.)

> Because it is so few lines it is much more sensible to have everyone duplicate that little snippet manually

Mine's about 100 LOC. There's a lot you can get wrong. Having a way to use a known working version and update that rather than adding a hundred potentially unnecessary lines of code is a good thing. https://github.com/mikemaccana/fetch-unfucked/blob/master/sr...

> import a library and write interceptors for that...

What you suggesting people would have to intercept? Just import a library you trust and use it.

Your wrapper does do a bunch of extra things that aren't necessary, but pulling in a library here is a far greater maintenance and security liability than writing those 100 lines of trivial code for the umpteenth time.

So yes you should just write and keep those lines. The fact that you haven't touched that file in 3 years is a great anecdotal indicator of how little maintenance such a wrapper requires, and so the primary reason for using a library is non-existent. Not like the fetch API changes in any notable way, nor does the needs of the app making API calls, and as long as the wrapper is slim it won't get in the way of an app changing its demands of fetch.

Now, if we were dealing with constantly changing lines, several hundred or even thousand lines, etc., then it would be a different story.

But you said so yourself they are necessary… otherwise you would just use fetch. This reasoning is going around in circles.

Why the 'but'? Where is the circular reasoning? What are you suggesting we have to intercept?

- Don't waste time rewriting and maintaining code unecessarily. Install a package and use it.

- Have a minimum release age.

I do not know what the issue is.

but it does for massive DDoS :p

> Likewise, every response I get is JSON.

fetch responses have a .json() method. It's literally the first example in MDN: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/U...

It's literally easier than not using JSON because I have to think about if I want `repsponse.text()` or `response.body()`.

that's such a weak argument. you can write about 20 lines of code to do exactly this without requiring a third party library.

Helper functions seem trivial and not like you’re reimplementing much.

Don't be silly, this is the JS ecosystem. Why use your brain for a minute and come up with a 50 byte helper function, if you can instead import a library with 3912726 dependencies and let the compiler spend 90 seconds on every build to tree shake 3912723 out again and give you a highly optimized bundle that's only 3 megabytes small?

> usage patterns

IMO interceptors are bad. they hide what might get transformed with the API call at the place it is being used.

> Likewise, every response I get is JSON. There's no reason to manually unwrap the response into JSON every time.

This is not true unless you are not interfacing with your own backends. even then why not just make a helper that unwraps as json by default but can be passed an arg to parse as something else

One more use case for Axios is it automatically follows redirects, forwarding headers, and more importantly, omiting or rewriting the headers that shouldn't be forwarded for security reasons.

fetch automatically follows redirects, fetch will forward your headers, omitting or rewriting headers is how security breaks… now a scraper got through because it’s masquerading as Chrome.

What does an interceptor in the RequestInit look like?

A wrapper function around fetch… that’s what interceptors are…

It also supports proxies which is important to some corporate back-end scenarios

fetch supports proxies